Drilled or External Overflow?

[Aquattro]

Both are fine, externals can be setup to not fail. But, my internal takes up less room, and makes things a bit cleaner looking. I guess I don't like things hanging on the edge of the tank. But given the choice, with an empty tank, I would still recommend an internal. The box portion can be customized for different needs and doesn't have to take up a lot of room.